Of Britain's senior actresses, there are three who can perform magic: Judi Dench, Maggie Smith and Vanessa Redgrave. And of Redgrave, the most erratic of the three, people often predict "She'll be either wonderful or terrible". In the event, however, many of her performances are examples of of both. She can be the most clumsy and most luminous of great actors in the course of a single performance. Currently she is appearing with the Royal Shakespeare Company in Euripides' Hecuba: a play staged in London only last autumn, with another of our finest actors, Clare Higgins, at the Donmar Warehouse. As Hecuba, the widowed queen of destroyed Troy, Redgrave is heart-stopping in the word's bad and good senses.

There are some 20 pauses when you'd swear she's forgotten the next line, and many more moments when her inflections, end-stoppings and droning chants are clumsy and ineloquent. Yet I hope I never forget the grim smile with which she stands in complete stillness to listen, for minutes on end, to the misogynistic reproaches of Polymestor, the traitor who has killed her last son: tragic magic. She has lost all; now she has killed his sons and blinded him; she is beyond accusations. She is sometimes far less good than Higgins (who was searing), yet she's more original and more surprising, and eventually she travels a larger emotional arc.